So Diarra seems like Rock 2.0. Not exactly highly regarded, but will be effective as a rebounder/garbage man.
His biggest influence will be if he convinces Diallo to come.
Let's break this down one at a time.
"Diarra seems like Rock 2.0" -- Maybe in terms of height and likely position; other than that, not really. They might have similar inclinations on the court (rebounding, being a wide-body presence), but Diarra should do them much better.
"Not exactly highly regarded" -- Only if you lump together everyone outside the Top 100 as "not highly regarded". Diarra will probably end up in the 100-150 range. Lubin was what, maybe 300. That's the difference between a bench-player on a high-major team and a low-major talent. Lubin was a major, major reach for a program at our level. It was true at the time we got him, and it was true up until he decided to leave.
"But will be effective as a rebounder/garbage man" -- True in the sense that Diarra will likely accomplish these things. Lubin never did, and never would have at this level.
"His biggest influence will be if he convinces Diallo to come" -- Possibly, but that's getting way ahead of ourselves.